Alzheimer’s disease
Alzheimer’s disease is a progressive neurological condition that changes the way a person thinks and functions over time. It is characterised by problems in thinking, learning, memory and judgment.
Alzheimer’s disease is often diagnosed in the mild dementia stage, when it becomes clear to family and doctors that a person is having significant trouble with memory and thinking that impacts daily functioning.
What is the difference between Alzheimer’s Disease and Dementia?
The terms Alzheimer’s and Dementia are often used interchangeably, but they are not the same thing. Dementia is a term used to describe a group of symptoms that affect intellectual and social abilities severely enough to interfere with daily function. These could be caused by Alzheimer’s disease, or any other disease with similar symptoms. Essentially, every person with Alzheimer’s disease has dementia, but not everyone with dementia has Alzheimer’s disease.
Types of Dementia
The symptoms and progression of the disease depend on the type of dementia a person has. The most commonly diagnosed forms of dementia are:
- Alzheimer’s disease
- Dementia with Lewy bodies
- Vascular dementia
- Parkinson’s disease
- Frontotemporal dementia
- Mixed dementia
Alzheimer’s disease is the most common form of dementia. It accounts for 60-80% of cases. It’s usually a slowly progressing disease, and can last for over a decade. It tends to develop slowly, and gradually worsens over several years. Eventually, the disease affects most areas of the brain. Memory, thinking, judgment, language, problem-solving, personality and movement can all be affected by the disease. It is not uncommon for people with dementia to become completely immobile and dependent at the end stages of the disease. As a terminal illness, Alzheimer’s disease progresses until the end of life, when extensive care is required.
Stages of Alzheimer’s Disease
There are up to seven stages of Alzheimer’s disease, but the features can be grouped into three broad phases. Defining a person’s disease stage assists physicians with treatment, and aids communication between clinicians. Not everyone will have all the symptoms associated with each stage.
1. Mild Alzheimer’s disease (early stage)
In the early stage of Alzheimer’s, a person may function independently. They may still drive a car, work and be part of social activities. Despite this, the person may feel as if he or she is having memory lapses, and friends, family or others close to the individual may begin to notice difficulties. Average duration of this stage is between 2 – 7 years.
- Increased forgetfulness
- Slight difficulty concentrating
- Decreased work performance
- Trouble remembering names when introduced to new people
- Increasing trouble with planning or organizing
Common difficulties include:
2. Moderate Alzheimer’s disease (middle stage)
Moderate Alzheimer’s typically lasts for around 3.5 years. As the disease progresses, dementia symptoms are more pronounced, and the individual with Alzheimer’s will require a greater level of care. A person may have greater difficulty performing tasks, such as paying bills, but they may still remember significant details about their life.
Symptoms may include:
- Decreased memory of recent events and one’s own personal history
- Difficulties managing finances or travelling alone
- Feeling moody or withdrawn, especially in unfamiliar situations
- Difficulty making decisions
- Requiring assistance in completing daily activities, such as picking an outfit, cooking bathing, and incontinence in some individuals
- Personality and behavioral changes, including suspiciousness and delusions or compulsive, repetitive behavior like hand-wringing or tissue shredding
- Changes in sleep patterns
3. Severe Alzheimer’s disease (late stage)
Dementia symptoms are severe in this final stage, and individuals require extensive assistance to carry out activities of daily living. They lose the ability to respond to their environment, to carry on a conversation and, eventually, to control movement. Significant personality changes may also take place. This stage may last up to 5 years.
At this stage, individuals may:
- Lose the ability to speak and communicate
- Require assistance with most activities
- Lose awareness of recent experiences as well as of their surroundings
- Become vulnerable to infections, especially pneumonia
- Experience changes in physical abilities like walking, sitting, and eventually swallowing
How is Dementia Diagnosed?
No single test can determine whether an individual has dementia. Diagnosis is based on a range of medical tests and a person’s medical history. If someone exhibits symptoms of dementia, their doctor will perform a physical exam, a neurological exam, a mental status test, and other laboratory tests to rule out other causes of their symptoms. Not all confusion and memory loss indicate dementia, however, so it is important to rule out other conditions such as drug interactions and thyroid problems.
References
Stages of Alzheimer’s Disease
https://www.alz.org/alzheimers-dementia/stages
What is Alzheimer’s Disease?
https://www.alzheimerswa.org.au/about-dementia/understanding-dementia/what-is-alzheimers-disease/
Alzheimer’s stages: How the disease progresses
Progression of Alzheimer’s disease
The Stages of Dementia
https://www.healthline.com/health/dementia/stages#diagnosis
Toward defining the preclinical stages of Alzheimer’s disease: Recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease
https://www.alzheimersanddementia.com/article/S1552-5260%2811%2900099-9/fulltext
Stages of Alzheimer’s & Dementia: Durations & Scales Used to Measure Progression: GDS, FAST & CDR